Come Friday afternoons during the summer, most city professionals look forward to powering down their computers and high-tailing it to the Hamptons.

Not Kristin Doggett and Lauren O’Shaughnessy.

The wedding planners and co-founders of the boutique planning business Bellafare are about to hit their professional crunch time: the intense culmination of months of prepping and plotting for their altar-bound clientele.

Right now, the Chelsea-based team is in the thick of it, with clients exchanging “I do’s” on four out of five weekends this month. Throw in the high emotions and high expectations inherent to working with demanding, dream wedding-seeking brides and grooms, and it’s no wonder Doggett says she has to remind herself, “It isn’t brain surgery. I’m not responsible for saving lives. It could be worse.”

Matrimonial madness is a fact of life for wedding professionals in the city, where the average Manhattan nups cost has jumped from $70,030 in 2010 to $76,678 in 2012, according to studies by XO Group Inc., which runs WeddingChannel.com and TheKnot.com. Nationwide, the $50.6 billion wedding service industry is expected to grow 2.3 percent over the next five years, according to a March report by the research firm IBISWorld. And although local entrepreneurs say the business of wedded bliss is more grunt work than glamour — and requires a unique skill set to succeed — the industry can offer a rewarding career.

For Doggett and O’Shaughnessy, whose company is among an estimated 12,000 to 14,000 metro-area businesses servicing the wedding industry, according to market research firm the Wedding Report, the best part of the job is dreaming up unique design schemes for each of their clients. They’ve created everything from a speakeasy-themed reception in Brooklyn to an opulent, black-tie soiree at the St. Regis.

But O’Shaughnessy says the creative process is just a fraction of their day-to-day responsibilities.

On top of overseeing every “I do” detail — an endeavor that has them playing part-designer, part-budget manager, part-mediator — the duo say they often end up serving as something of a punching bag to anxious brides and their families.

“Even with our most laid-back brides, there’s always a moment when they get super-stressed, usually a week before the wedding,” says Doggett, 29, a Carroll Gardens resident. “They’re freaking out for their own reasons and take it out on whoever’s there — and we’re always there.”

But, she adds, “we pretty much learn to block that out. If we were to dwell on that, we wouldn’t be able to do what we do.”

Pulling off once-in-a-lifetime, six-figure celebrations also demands a certain grace under pressure — especially in the face of emergencies like Hurricane Sandy’s aftermath. The duo had two weddings that weekend: a downtown reception that called for a venue and hotel change, and a New Jersey bash powered by generators that could have gone out at any minute.

“It was the most stressful week of our career,” says O’Shaughnessy, “but it proved that we are now capable of handling any situation.”

Although Doggett and O’Shaughnessy concede they’ll do almost anything for their full-service clients, last fall they decided to set some firm boundaries.

“We had to add a clause to our contract that we’re not housekeepers or dog walkers, because we’ve definitely been put in that position before,” says O’Shaughnessy.

David Wood, president of the Association of Bridal Consultants, likens planning a wedding to staging a Broadway show with only one performance — you’ve got a single shot to get it right.

“The most successful [wedding planners] can visualize a desired event and break it down into small, manageable steps,” he says. “This is a fun business, but it is not a glamorous one.”

The glam factor is probably the biggest misconception about the profession, says Xochitl Gonzalez, a partner and creative director at AaB Creates, a Tribeca-based firm specializing in high-end wedding bashes.

“People think it’s always romantic and creative, but it actually takes a very pragmatic person,” says Gonzalez, 35, of Fort Greene. “You don’t realize how much time you spend formatting spreadsheets and negotiating money.”

Gonzalez says she and her business partner, Mayra Castillo, spend “hundreds and hundreds” of hours planning each wedding — the majority of which is spent in the office, slaving over nitty-gritty details like table dimensions.

They receive between 10 and 30 résumés a week from “starry-eyed” internship-seekers and others hoping to break into the biz, few of whom grasp its grueling nature. “I would say 99.9 percent of interns who come work for us are not cut out for it, and are completely shocked by what’s happening,” says Gonzalez, citing the 15- or 16-hour days her team is expected to log on event days.

Gonzalez and Castillo, whose planning services start at $25,000, typically engage between 30 and 40 unique vendors for each of their big-ticket weddings. And on top of the management savvy, people skills and creative prowess required to pull off $250,000-and-up extravaganzas, Gonzalez says the biggest challenge is maintaining a collected, upbeat facade around brides on their big day.

“You have to put up a mask, [and] that can be stressful in itself,” says Gonzalez, who once went through with a wedding on the day her grandfather passed. “You can’t let the stress of your own personal life show.”

In recent years, a handful of niche wedding jobs, including honeymoon specialist and same-sex wedding planner, have cropped up in the city. And in these too, a certain cool, reassuring demeanor is key.

Julie Sabatino, whose independent wedding styling business, The Stylish Bride, is one of just a few in the city, says helping brides and their wedding parties find the perfect attire requires empathy and sincerity.

“What I do is so much based on a personal relationship and getting to know them really well,” says the 36-year-old Upper West Side resident, who styles 15 weddings a year. “I really love the emotional part of it.”

And when she’s faced with a disappointing dress fitting — or worse, a disappointed mother of the bride?

“The most important thing is to be calm, and make them know you have it under control,” she says.

Amanda Shackleton, a hairstylist and makeup artist behind NY Bridal Beauty, has been working weddings for more than a decade — and knows the 50 or so weddings she’ll oversee this year demand more than mere skill with a curling iron.

“The aim is to make them happy and keep them calm,” says Shackleton, 48, who lives and works in the Flatiron District. “You have to have a bit of psychology skills as well.”

She’s used to the occasional dramatics — like one young bride who locked herself in the bathroom when it was time to go down the aisle — and also the hectic schedule during the summer months.

“Sometimes you want to go away for the weekend with your friends to the Hamptons, and you just can’t do that,” she says. “Usually your weekend is Monday and Tuesday.”

“Getting to go to wedding functions at the best, hippest, exciting venues in NYC on weekends — how can you beat that?” muses the Tribeca-based shutterbug, 50. “I’m doing what I love. And it’s a world I wouldn’t be invited into if it weren’t for what I do.”

Even though “nervous brides and very concerned moms are par for the course,” Masana says there’s a reason he hasn’t left the industry for a gig with more steady emotions — and fewer drunk guests.

“I’m in a world where I’m forever meeting young couples in love, working with very happy occasions,” he says. “There’s such a rejuvenating atmosphere.”

For Bellafare’s Doggett and O’Shaughnessy, the payoff comes from delivering the best day of their clients’ lives — even if it means kissing their own summer weekends goodbye. “To feel the love that’s in the room,” Doggett says, “it’s totally worth it for us.”